As broadcasters continue the transition from analog television to digital video television, the television production process is increasingly conducted in an all-digital domain, that is, from the initial camera shot to the display in the consumer's living room. This move to digital technology permits broadcasters to simultaneously broadcast multiple video streams using a single connection. Indeed, for popular live events, broadcasters typically deploy mobile broadcast units to route and manipulate, i.e., producing the numerous video streams that come from respective cameras throughout the event before being transmitted.
An approach to manipulating and monitoring the video streams is a multiviewer, which typically includes a monitor and associated processor receiving the high resolution, digital video streams. The processor scales the video stream to fit all the video streams onto a single display. Some multiviewers use a plurality of monitors, thereby permitting the viewing of even more video streams. A potential drawback to the typical multiviewer is the difficulty in rearranging the video streams on the monitor in real time. For example, a user viewing the multiviewer monitor displaying four video streams split equally over quarters of the monitor may desire to expand a first video stream and correspondingly reduce the other video streams. This operation may cause the processor to adjust scaling operations in real time based upon requests from the user. More specifically, to provide advanced features to the user, the typical multiviewer may have to include significant hardware to provide adequate processing power, thereby possibly increasing the form factor and housing size to undesirable levels.
Some exemplary multiviewer systems include the DX series from present assignee Harris Corporation. The DX series Multiviewers delivers modular configurations for 4, 8, 12 or 16 SDI or composite inputs typically using different input modules, with auto detect of NTSC, PAL or SDI formats. Composite, component, SDI and line doubled VGA outputs provide customers with a wide range of flexible display options. Front panel controls and remote control via RS-232/422 provide the user with the ability to view real-time multiple images in various pre-configured displays. Optional software allows the user configuration of displays, and multi-system control, while options also exist for in-picture audio monitoring of SDI embedded audio. Standard alarm features include loss of video sync, black picture and frozen picture detection.
Another exemplary multiviewer system is the 7767VIP4 signal monitoring module from the Evertz corporation of Burlington, Ontario, Canada. The module simultaneously accepts, auto-detects, analyzes and displays four synchronous or asynchronous HD/SD/Analog video signals. An additional fifth computer graphic input may be used for display of a dynamic background image. A similar multiviewer system is disclosed in U.S. Pat. No. 7,023,488 to Szybiak et al.
Despite the advantages of such multiviewer systems, further enhancements may be desirable in some applications. For example, system memory constraints often impose restrictions on the number of video inputs that may be simultaneously displayed. Additionally, the ability of such systems to display added graphic content (e.g., backgrounds, indicators, etc.) along with the video inputs on the display may be encumbered by the requirement for separate inputs for such content, or for performing offline modifications to video inputs or display templates, for example.